Sankan-seibatsu (the conquest of three countries in old Korea) (三韓征伐)

Sankan-Seibatsu (the conquest of three countries in old Korea) was written in the war affairs of the "Nihonshoki" (Chronicles of Japan), on the military expeditions against Silla (pronounced "Shiragi" in Japanese: Kingdom of ancient Korea) by the Empress Jingu who was a descendant of Prince Amenohiboko of Silla. After Silla surrendered, two remaining countries from the three (Paekche [pronounced "Kudara" in Japanese: Kingdom of ancient Korea] and Koguryo [pronounced "Kokuri" in Japanese: Kingdom of ancient Korea]) surrendered to Japanese authority, one after another; so, this war affair came to be known as the Sankan-Seibatsu. However, in some cases it was called the "Conquest of Silla."

An analysis before the war

It is said that Korea became a dependency to Japan by 'Sankan-Saibatsu' after "Nihonshoki" was finished.
A reaction in those Japanese who favored this opinion would be an acceptance of Korea as 'a dependency to Japan' or point of fact 'used to be a dependency to Japan.'
In order to justify an advance upon Korea, Hideyoshi TOYOTOMI aggressively used a legitimate reason (After the Sankan-Seibatsu Korea is dependency to Japan, which has the right to rule the country); then executed the battle of Bunroku and Keicho (Japanese invasions of Korea, two campaigns to attack Korea). During the Edo period, scholarly researchers in the discipline of Japanese literature and culture came to widely accept the validity of the theories (for example, "Bukejiki" [the account of the military houses] by Soko YAMAGA); this positively supported the Sankan-Seibatsu, and the subsequent use of the Sankan-Seibatsu was legitimate as a central thesis for the battles of Bunroku and Keicho.

It continued to support this theory in and after the Meiji period. Japanese militaristic authorities utilized this theory as background support in many ideological situations; on the occasion of rising the Seikanron (Debate to conquer Korea), merging Korean Empires (the annexation of Korea) practically and when Nikkan Doso Ron (Japan and Korea have a common ancestor) was birthed, then the assimilation policy in foreign lands (for example, imperialization education on Korea during Japan's colonial rule) was implemented and went forward. Under Kokoku Shikan (emperor-centered historiography which is based on state Shinto), all Japanese shared a common sense that it was taboo to present a doubtful comment about content of the kiki (Kojiki ["A Record of an Ancient Matter"] and Nihonshoki ["Chronicles of Japan"]) and that the existence of Empress Jingu was a historical fact.

Analysis after the war

In postwar history, Japanese historians and scholars gained freedom and separation from the Kokoku Shikan and progressed in their positive research into the kiki. This resulted in the mainstream of academic world's theory that the real existence of Empress Jingu could not be proved, due to the two factors: 'Sankan-Seibatsu' was written without any definite supporting statements; and it was written with many inclusive elements of mythological exaggerations. The militaristic advance into the Korean peninsula by Wa (also pronounced "Yamato" in Japanese: ancient Japan) in the fourth century is treated in completely different historical materials of the same historical period such as: Gwanggaeto Stele (Gwanggaeto Stele was built in '411' by King Jangsu of Goguryeo Jian, Jinling Province, China) and the Seven-Branched Sword (Nanatsusaya no Tachi in "Nihon shoki").

There was a time when some scholars tended to theorize that the Imperial Japanese Army tried to legitimize their militaristic advance into Korean peninsula by Empire of Japan; therefore, the efforts of the Imperial Japanese Army were directed in altering any inconvenient historical facts on Inscription on the Gwanggaeto Stele (a theory introduced by Rijinhi, a Professor of Wako University). However, this theory is almost denied at present.
(Inscription on the Gwanggaeto Stele; the oldest engraved print found; it is identical to the one retrieved by the old Imperial Japanese Army; 'Put a period to the Debate about the Alteration'; the Yomiuri Shimbun, April 12, 2006, page 12.)

Additionally, the events of the Wakoku (Japan, also known as Yamato sovereignty [ancient Japan sovereignty]) from the late fourth century saw a steady progression in Japanese militaristic advancement into the southern regions of the Korean Peninsula; reports of this fact were revealed in several documents of historical materials, and archaeological artifacts. The Inscription on the Gwanggaeto Stele said that, as far as a reading according to a commonly accepted theory, Wakoku progressed in leading the Japanese militaristic advance into the Korean Peninsula to make Paekche and Silla serve as vassal countries and had a furious battle with Koguryo.
This interpretation of the inscription was then established as the universally established evaluation, granting the fact in 'Some components of the statements were exaggerations of a great achievement, but most of the components reflected accurately on historical facts.'
Furthermore, regarding discription in Chinese history books (such as "Sungshu" [Book of the Sung dynasty]), there is an opinion that there was supportive evidence of Wakoku having had some influential power over the small states in the Southern Korean peninsula." A Korean history book, "Samguk Sagi" (History of the Three Kingdoms), also provided evidence of these same events; there were details describing repeated invasions into the Korea Kingdoms by Wa and the taking hostage of the princes of Silla and Paekche. (Korean literature on Wa and Wajin [Japanese people]) Later, artifacts of the Wakoku (Japan) were discovered in the excavation of the zenpo-koenfun (keyhole-shaped mound) in area of old Gaya (Mimana) in southern Korea. Those artifacts were considered to be proof of the theory, the invasion of the Korean Kingdoms by Wakoku.

Those evidences, even dismissing the tale of 'Sankan-Seibatsu,' would be determinate factor in the foundation of the theory that Wa progressed in his militaristic advance into the Korean peninsula during the later portion of the fourth century as historical fact. This is the mainstream in the academic world of ancient history. However, there is no description such as 'Attacks by Okinagarashihime or the Queen of Wa' on the Gwanggaeto Stele and Korean materials including "Samguk Sagi (History of the Three Kingdoms)," and "Sangokuiji Yusa (an Anecdotal History of the Three Kingdoms in Ancient Korea)." Of this fact 'Sankan-Seibatsu by Empress Jingu' in kiki (Kojiki and Nihonshoki) itself is doubtful. Samguk Sagi was less mistaken on this chronology of applicable historical data in comparison to Nihonshoki (Chronicles of Japan) and the sexagenarian cycle between the Gwanggaeto Stele and the Samguk Sagi had only one years difference. Thus, during this period in Korea, it seems that Korean people generally could record documents written by letters. In comparison, the kiki (Kojiki and Nihonshoki) has no description of any furious battles with Koguryo, written on the Gwanggaeto Stele. So, this indicates Japanese people during this period did not record documents concretely written by letters. It was during this period in the investigation of Japanese history, scholars researching the external articles of "Nihonshoki," in a break through, identified through calculations was the correct dating of the events; the method used in calculation, was the movement backward in years by two cycles (one cycle = 60 years), 120 years, to the estimated sexagenarian cycle in the book. The dating used in the Nihonshoki seems to have been based upon the three books of Paekche (Original Records of Paekche, Records of Paekche, and The New Selection of Paeche). Originally, a tradision native to Japan has no recorded articles about the Oriental zodiac; so, scholars believed in the extreme scarcity of an identifiable foundation for these historical facts.
Currently, the academic world has the theory that the rationale in the subjugation of Silla was formed in Japan with the tale of Sankan-Seibatsu; in consideration of the fact in which Sankan-Seibatsu was actually written at some distant point in time. (There was an article in the "Shoku Nihongi" [a continuation of Nihonshoki; an imperially commissioned Japanese history text] about a visiting envoy of Silla, who became outraged upon hearing the official story of the Empress Jingu.)
Scholars formed a hypothesis that Japan may have fabricated the tale of Sankan-Seibatsu based on a vague memory of a battle on the Korean peninsula and a historical event of an Imperial visit to the Tsukushi Asakra Palace during the expedition to Silla by Empress Saimei.
(A theory by Masaaki UEDA and Kojiro NAOKI)